(1) Field of the Invention
The invention relates to a household appliance, in particular a washing machine, a dishwasher or the like, having a liquid circuit and a pump having a pump casing with a heating element for heating the liquid. The heating element has a heat conducting contact area with at least a partial form fit into the outer shape of the pump casing with the heat conducting contact area being at least half the size of the entire outer area of the heating element. More particularly the invention pertains to a heating element that is inserted into an outer depression of the pump casing such that the outer depression forms a protrusion on the inside of the pump casing.
(2) Description of Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
Document 197 36 794 A1 has disclosed a pump for a dishwasher in which the heating element has been integrated into the pump in the form of a throughflow heater. The construction described therein involves adaptation pieces in the bottom of the machine, in which case the pump cannot be operated as a separate component.
Document DE 201 07 363 U1 has disclosed a water pump in which a heating element is inserted into a continuous bead on the circumference.
Furthermore, document DE 199 16 136 A1 has disclosed a liquid pump for a dishwasher, into which pump a heating element is likewise integrated. In this embodiment, the heating element is fitted on the outside or on the inside of a pump casing which, with the exception of connection pieces, is closed. In this abovedescribed embodiment, expenditure on manufacture and assembly is already considerably reduced as compared with the previous prior art.
Document DE 199 32 033 describes a water pump in which a flat heating element is joined to a cylindrical pipe connection piece and, in the process, additionally bears with one side against the bent-away cover of the pump casing. In this way, approximately half of the surface of the heating element of essentially rectangular cross section bears against the pump casing or the pipe connection piece. A relatively large contact area is not possible with this construction.